Electrical connector with means for securing conductor loops about screws



Nov. 16, 1954 K. R. SUNDERHAUF 4,

ELECTRICAL CONNECTOR WITH MEANS FOR SECURING CONDUCTOR LOOPS ABOUT SCREWS Filed March 22, 1949 INVENTOR.

United States Patent Ofiice 2,694,800 Patented Nov. 16, 1954 ELECTRICAL CONNECTOR WITH MEANS FOR SE- CURING CONDUCTOR LOOPS ABOUT SCREWS Karl R. Sunderhauf, New'York, N. Y.

Application March 22, 1949, Serial No. 82,710

1 Claim. (Cl. 339-269) This invention relates to connectors for electrical wires 'or of similar conductors which are either made of solid or stranded material.

It is an object of the invention to provide means permitting simple but effective construction of a connector of the aforesaid type which secures the wire or similar conductor firmly in place and to a predetermined extent and which prevents accidental disconnection of the wire from the connector.

It is another object of this invention to provide means affording ready transformation of a conventional binding screw or head of a screw into a connector device which includes a guide for the wire, whereby the wire is tightly clamped for electrical and mechanical connection with said binding screw and extends beyond said guide for connection with a power source, consumer unit and the like.

It is a further object of the present invention to provide means permitting easy transformation of a conventional wire connector of any electrical consumer appliance, such as of a switch, to an electrical connector device according to the invention, which device holds the wire or similar conductor in place and anchors the wire end in such a manner that a wire coil is provided which afiords a uniform contact between the binding post or screw and the guide or base of the guide.

Yet a further object of the invention is to provide means rendering possible the utilization of a part of the conventional slot of binding posts or screw bolts to anchor therein an end of the aforesaid wire or similar conductor.

Other objects of the present invention are to provide a terminal connector for electrical wires or similar conductors which is of simple construction, inexpensive to manufacture, easily adjusted for the connection of the wire to the terminal strip, has a minimum number of parts, and is convenient to use and efficient in operation.

For other objects and for a better understanding of the invention, reference may be had to the following detailed description taken in connection with the accompanying drawing, in which Fig. 1 is a fragmentary top plan view of a standard toggle switch employing the wire connector or terminal and embodying the features of the present invention and constructed according to one form of the invention.

Fig. 2 is a fragmentary side elevational view of the standard toggle switch and of the wire connector or terminal shown in Fig. 1.

Fig. 3 is an enlarged fragmentary sectional view of the terminal strip and binding screw shown in Figs. 1 and 2.

Fig. 4 is a perspective view of the binding screw of Fig. 3 alone, but somewhat modified.

Fig. 5 is a perspective view of a modified binding screw wherein the radial slot is in alignment with the regular transverse slot which receives the screw driver shank.

Fig. 6 is an end elevational view of the terminal strip with the screw secured downwardly upon a wire, both the strip and the screw being of the type shown in Figs. 1 and 2.

Fig. 7 is a perspective and exploded view of a terminal assembly of a modified form of the invention and employing a cupped ring for receiving the wire and the screw head.

Fig. 8 is a sectional view taken through the assembly of the parts shown in Fig. 7.

Fig. 9 is a fragmentary perspective view of a still further form of the invention wherein the terminal strip has multiple openings for receiving plural wires extended about the terminal screw.

Fig. 10 is a view showing the specific screw of Fig. 5 applied to the terminal strip of Fig. 3.

Referring now particularly to Figs. 1 to 6, 10 represents a standard toggle switch having a handle 11 and a securing strap 12 for holding the switch in a receptacle, not shown. Extending across the top of the switch body is a terminal strip 13 having struck up portions 14 and 15 on the end thereof to provide a slot 16 for retaining terminal wire 17 which is extended therethrough for connection with a terminal screw 18 having a screw head 19 with a transverse slot 21 therein for receiving the shank of a screw driver for the purpose of being tightened through the terminal strip with which it has threaded engagement. The bottom of the head 21 has radially extending serrations 22 for providing a good grip upon the wire and for freeing the same of enamel which may be disposed thereon. Also in the screw head 18 is an inwardly extending slot 23 for receiving the end of the wire 17 to prevent its movement and to stay itwith the screw head 19 as the screw is turned to tighten the serrations upon the wire and to fix the wire to the top face of the terminal strip 13. A short bend is placed in the wire end, as indicated at 24, and this end is projected upwardly into the slot 23 at the beginning of the tightening action of the screw. The wire is first laid flat upon the strip with the bent up end 24 registering with the slot 23 of the binding screw. As the screw is turned for tightening purpose, a loop, as indicated in Fig. 1, is formed by the wire about the screw threads. Control of the wire is accordingly maintained during this assembly operation and an even and perfect loop is formed without portions of the wire end protruding from the periphery of the screw head 19.

As seen in Fig. 4, slot 23a extends radially instead of in the direction of a chord as illustrated in Fig. 3.

As shown in Fig. 5, the slot can also be aligned with the transverse slot 21, as indicated at 23b. A wire will be placed within the slot 23b in the same manner as above described and the screw will be turned by means of the screw driver without interference from the wire end 24.

In Figs. 7 and 8, there is shown a modified form of the invention wherein the wire end is retained in a cupshaped member or ring 27 having a bottom 28 with an opening therein, as indicated at 29, through which a terminal screw 31 is passed for the connection of the terminal wire and the ring 27 with a terminal strip 32. This terminal strip has a threaded opening 33 for receiving the screw 31 and has turned up end projections 34 and 35 for providing a guiding slot 36 through which the wire is extended. The ring 27 has a lip 37 which is dropped down and which extends into the slot 36 to prevent the rotation of the ring with respect to screw 31. A recess 38 is provided in the side of the ring above the lip 37 and through this recess the wire end extends. The wire, before being placed in this assembly, can be formed with a loop of a size adapted to fit the ring 27 and rest upon the bottom 28 thereof. The screw 31 has a head 39 with a standard transverse slot 41 therein. This head will move downwardly into the ring so as to be fully enclosed by the same, the wire loop, as indicated at 42, being thus forced onto the bottom of the ring 27 to be retained therein and to be fully covered thereby. With this arrangement, there is no likelihood of the wire loop becoming loose due to vibrations, shocks, etc., and of being separated from the binding screw. The ends of the wire loop will be fully hidden which is of particular importance when conducting high voltage currents, to avoid corona effects. The ring, through the projection 37 within the slot 36, will be locked in place against rotation about the screw 31.

In Fig. 9, there is shown a still further form of the invention wherein the terminal strip 44 has three upstanding projections 45, 46 and 47 spaced from one another to provide slots 48 and 49. Two wires 51 and 52 are passed through the slot 48 and about a screw 53. In order that the ends of the wires b made secure against tuming and displacement from beneath the head of the screw while the screw is being tightened, these wire ends are extended through the slot 49. Accordingly, the wires can be positively retained while being tightened upon the terminal strip by the screw 53.

It should now be apparent that there has been provided according to the invention a terminal connection wherein the Wires can be kept secure and protected on the terminal post and substantially enclosed at all times. The construction of the parts is such that with the wires placed under the head of the screw, they are retained there even while the screw is being adjusted or turned in the terminal strip. Control of these wires is not lost during the tightening operation.

While various changes may be made in the detail construction, it shall be understood that such changes shall be within the spirit and scope of the present invention as' defined by the appended claim.

What is claimed is:

A connector device for an electric Wire comprising a terminal strip provided with a tapped hole, grooved guide means on said terminal strip directed substantially parallel to the surface of the latter, and Wire engaging means including a threaded shank mating engaging means further including flange means on said threaded shank and rotatable with the latter relative to said surface of said terminal strip, the top surface of said flange means being provided with a screw driver slot including a slot part coinciding with the latter and extending from the periphery of said flange through the latter inwardly and terminating at said threaded shank, whereby an extremity of said wire disposed beyond said looped wire may be received in said slot part in a position substantially perpendicular to that of said wire in said guide means to thereby anchor said wire against displacement with respect to the surface of said terminal strip and to provide secure electrical and mechanical connection of said wire with said threaded shank.

References Cited in the file of this patent UNITED STATES PATENTS Number. Name Date D, 32,924 Keeler July 10, 1900 883,201 Johnson Mar. 31, 1908 1,243,716 Cuthbert Oct. 23, 1917 1,258,657 Cuthbert Mar.. 12, 1918 1,321,880 Benjamin Nov. 18, 1919 1,837,893 Begard' Dec. 22, 1931. 1,847,738 Wiegand Mar. 1, 1932 2,070,566 Dobbs Feb. 16, 1937 2,326,090 Yadon Aug. 3, 1943 

